DThe Indian lemon or lime (Citrus acida or C. medica var. acida) is sour, bitter, astringent and cooling and sweet post-digestively. Though it does not aggravate normal pitta, it must be used with caution once pitta is elevated. Its juice is applied externally on mosquito and other bites, on skin eruptions and on the scalp to remove dandruff. It is used in treating all sorts of digestive disorders, including diarrhoea and dysentery and it is added to food to improve both digestion and appetite. It has also been used in treating fevers, constipation, diabetes, diseases of the liver and spleen, poisoning, gout, rheumatoid arthritis and even cataract (the brave put drops of it into their eyes). Some authorities claim that there is not disease that this fruit, properly prepared, cannot cure.

References: Ayurveda Life Health and Longevity by Robert E. Svoboda - Penguin Books.